Pet fountain filter



FIG. 1 is a top, front, right perspective view of a pet fountain filter of my new design;

FIG. 2 is a bottom, back, left side perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a back view thereof;

FIG. 5 is a left view thereof;

FIG. 6 is a right view thereof;

FIG. 7 is a top view thereof; and,

FIG. 8 is a bottom view thereof. 

CLAIM I claim the ornamental design for a pet fountain filter, as shown and described. 